It's Only Factorials

Computer Science Level 2

Do the following snippets of code always return the same output given a positive integer input?

def factorial(n):   
   factorial = 1   
   for number in range (1, n):   
      factorial = factorial * number   
   return factorial

def factorial(n):   
   if n == 1 :   
      return 1   
   else:   
      return n*factorial(n-1)

Yes, always No, not always

1 solution

Arulx Z
Dec 11, 2015

The function xrange(x, y) is inclusive of $x$ while exclusive of $y$ . So the function only loops until $y-1$ .

Hence the first code return $(n-1)!$ while the second code return $n!$ .

Great! When coding, it is important to know what all of the terms mean, instead of just guessing at what they are.

The question does state "given a positive integer input".

Calvin Lin Staff - 5 years, 6 months ago

Oh. I missed that. I found the flaw. I've fixed my answer. I just got a little lucky :p.

Arulx Z - 5 years, 6 months ago